1398638 has 4 divisors (see below), whose sum is σ = 2097960. Its totient is φ = 699318.

The previous prime is 1398623. The next prime is 1398659. The reversal of 1398638 is 8368931.

It is a semiprime because it is the product of two primes.

It is an Ulam number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 349658 + ... + 349661.

It is an arithmetic number, because the mean of its divisors is an integer number (524490).

2^1398638 is an apocalyptic number.

1398638 is a deficient number, since it is larger than the sum of its proper divisors (699322).

1398638 is an equidigital number, since it uses as much as digits as its factorization.

1398638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 699321.

The product of its digits is 31104, while the sum is 38.

The square root of 1398638 is about 1182.6402665223. The cubic root of 1398638 is about 111.8326049532.

The spelling of 1398638 in words is "one million, three hundred ninety-eight thousand, six hundred thirty-eight".